scholarly journals The efficacy of black tea in ameliorating endothelial function is equivalent to that of green tea

2007 ◽  
Vol 99 (4) ◽  
pp. 863-868 ◽  
Author(s):  
Nicoline Jochmann ◽  
Mario Lorenz ◽  
Amélie von Krosigk ◽  
Peter Martus ◽  
Volker Böhm ◽  
...  
Keyword(s):  
Endothelial Function ◽  
Green Tea ◽  
Human Subjects ◽  
Black Tea ◽  
Flow Mediated Dilation ◽  
Water Control ◽  
Aortic Endothelial Cells ◽  
Beneficial Effects ◽  
Bovine Aortic Endothelial Cells ◽  
Green And Black Tea

Consumption of tea has been shown to improve endothelial function. It is assumed that catechins are the tea components responsible for these beneficial effects. In black tea, catechin concentrations are significantly lower than in green tea. The present study was designed to compare green and black tea with regard to amelioration of endothelial function. Endothelial function in response to both teas was assessed in bovine aortic endothelial cells (BAEC) and rat aortic rings. To elucidate whether these findings are also applicable to humans, flow-mediated dilation (FMD) and nitro-mediated dilation (NMD) were assessed by ultrasound in twenty-one healthy women before and 2 h after consumption of green and black tea (2 h of FMD and NMD), in comparison with water (control). In BAEC, green and black tea significantly increased endothelial NO synthase activity to the same extent. Similarly, both teas induced comparable endothelial-dependent vasodilation in rat aortic rings. In human subjects, ingestion of green and black tea led to significant increases in FMD: from 5·4 (sd 2·3) to 10·2 (sd 3) % (baseline-adjusted difference (BAD) for 2 h of FMD, green tea v. water: 5·0 (95 % CI 3·0, 7·0) %; P < 0·001) and from 5 (sd 2·6) to 9·1 (sd 3·6) % (BAD for 2 h of FMD, black tea v. water: 4·4 (95 % CI 2·3, 6·5) %; P < 0·001), respectively. The increase in FMD was not significantly different between the two tea preparations (BAD for 2 h of FMD, green tea v. black tea: 0·66 (95 % CI − 0·76, 2·09) %; P = 0·36). NMD did not vary between any of the groups. In conclusion, green and black tea are equally effective in improving endothelial function.

scholarly journals Tea Polyphenols in Promotion of Human Health

Nutrients ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 39 ◽  
Author(s):  
Naghma Khan ◽  
Hasan Mukhtar
Keyword(s):  
Green Tea ◽  
Animal Studies ◽  
Neurological Diseases ◽  
Black Tea ◽  
Polyphenolic Compounds ◽  
Tea Polyphenols ◽  
Beneficial Effects ◽  
Gallocatechin Gallate ◽  
Prevention Of Cancer ◽  
Pharmacologically Active

Tea is the most widely used beverage worldwide. Japanese and Chinese people have been drinking tea for centuries and in Asia, it is the most consumed beverage besides water. It is a rich source of pharmacologically active molecules which have been implicated to provide diverse health benefits. The three major forms of tea are green, black and oolong tea based on the degree of fermentation. The composition of tea differs with the species, season, leaves, climate, and horticultural practices. Polyphenols are the major active compounds present in teas. The catechins are the major polyphenolic compounds in green tea, which include epigallocatechin-3-gallate (EGCG), epigallocatechin, epicatechin-3-gallate and epicatechin, gallocatechins and gallocatechin gallate. EGCG is the predominant and most studied catechin in green tea. There are numerous evidences from cell culture and animal studies that tea polyphenols have beneficial effects against several pathological diseases including cancer, diabetes and cardiovascular diseases. The polyphenolic compounds present in black tea include theaflavins and thearubigins. In this review article, we will summarize recent studies documenting the role of tea polyphenols in the prevention of cancer, diabetes, cardiovascular and neurological diseases.

scholarly journals The Association between Green and Black Tea Consumption on Successful Aging: A Combined Analysis of the ATTICA and MEDiterranean ISlands (MEDIS) Epidemiological Studies

Molecules ◽  
2019 ◽  
Vol 24 (10) ◽  
pp. 1862 ◽  
Author(s):  
Nenad Naumovski ◽  
Alexandra Foscolou ◽  
Nathan M. D’Cunha ◽  
Stefanos Tyrovolas ◽  
Christina Chrysohoou ◽  
...  
Keyword(s):  
Green Tea ◽  
Successful Aging ◽  
Coffee Consumption ◽  
Black Tea ◽  
Epidemiological Studies ◽  
Tea Consumption ◽  
Successful Ageing ◽  
Mediterranean Islands ◽  
Combined Analysis ◽  
Green And Black Tea

Tea is one of the most-widely consumed beverages in the world with a number of different beneficial health effects, mainly ascribed to the polyphenolic content of the tea catechins. The aim of this study was to examine the consumption of green, black, or no tea, in relation to the previously validated successful ageing index (SAI; higher values “healthier” ageing) in a combined analysis of adults aged >50 years old from the ATTICA (n = 1128 adults from Athens, Greece metropolitan area) and the MEDiterranean Islands Study (MEDIS) (n = 2221 adults from various Greek island and Mani) studies. After adjusting for age, sex, smoking, and coffee consumption, green tea was positively associated with SAI (b ± SE: 0.225 ± 0.055, p < 0.001), while black tea was negatively associated with SAI (unstandardized b coefficient ± Standard error: −0.807 ± 0.054, p < 0.001). Green tea (vs black tea) consumption, had higher odds of a SAI of over 3.58 out of 10 (OR: 1.77, 95% CI: 1.38–2.28). Green tea consumption was also associated with higher levels of physical activity (p < 0.001) and reduced likelihood of hypertension (p = 0.006) compared with black tea. Two possible mechanisms are that green tea possesses high levels of catechins such as (−)-epigallocatechin 3-gallate and l-theanine compared with black tea. Therefore, the present analysis supports both the role of green tea constituents in successful ageing, as well as its role as an important component of an overall healthy diet in adults aged 50 years and over from these two epidemiological studies.

Effect of different doses of un-fractionated green and black tea extracts on thyroid physiology

2010 ◽  
Vol 30 (8) ◽  
pp. 884-896 ◽  
Author(s):  
Amar K Chandra ◽  
Neela De ◽  
Shyamosree Roy Choudhury
Keyword(s):  
Thyroid Gland ◽  
Green Tea ◽  
Harmful Effect ◽  
Black Tea ◽  
Green Tea Extract ◽  
Male Rats ◽  
Thyroid Peroxidase ◽  
Black Tea Extract ◽  
Green And Black Tea ◽  
Tea Extract

Tea is a rich source of polyphenolic flavonoids including catechins, which are thought to contribute to the health benefits of it. Flavonoids have been reported to have antithyroid and goitrogenic effect. The purpose of this study was to evaluate whether high doses of green and black tea have a harmful effect on thyroid physiology. Un-fractionated green and black tea extracts were administered orally to male rats for 30 days at doses of 1.25 g%, 2.5 g% and 5.0 g%. The results showed that green tea extract at 2.5 g% and 5.0 g% doses and black tea extract only at 5.0 g% dose have the potential to alter the thyroid gland physiology and architecture, that is, enlargement of thyroid gland as well as hypertrophy and/or hyperplasia of the thyroid follicles and inhibition of the activity of thyroid peroxidase and 5′-deiodinase I with elevated thyroidal Na+, K+-ATPase activity along with significant decrease in serum T3 and T4, and a parallel increase in serum thyroid stimulating hormone (TSH). This study concludes that goitrogenic/antithyroidal potential of un-fractionated green tea extract is much more than black tea extract because of the differences in catechin contents in the tea extracts.

scholarly journals Superoxide-mediated inactivation of nitric oxide and peroxynitrite formation by tobacco smoke in vascular endothelium: studies in cultured cells and smokers

2009 ◽  
Vol 296 (6) ◽  
pp. H1781-H1792 ◽  
Author(s):  
Gonzalo Peluffo ◽  
Pablo Calcerrada ◽  
Lucia Piacenza ◽  
Nelson Pizzano ◽  
Rafael Radi
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Endothelial Dysfunction ◽  
Tobacco Smoke ◽  
Endothelial Nitric Oxide Synthase ◽  
Flow Mediated Dilation ◽  
Aortic Endothelial Cells ◽  
Bovine Aortic Endothelial Cells ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide

Tobacco smoke is known to cause nitric oxide (·NO) inactivation and endothelial dysfunction. In this work we evaluated the interplay between·NO and superoxide (O2·−) radicals and the consequent impact on·NO bioavailability and nitroxidative stress in bovine aortic endothelial cells exposed to cigarette smoke extract (CSE) and in smokers. Bovine aortic endothelial cells in the presence of CSE triggered O2·−production as indicated by spin-trapping electron paramagnetic resonance experiments. O2·−was produced both extracellulary (3.4 vs. 1.0 nmol·h−1·mg−1; CSE vs. control; cytochrome c3+reduction assay) and intracellularly (40% inhibition of cytosolic aconitase). CSE also led to the production of peroxynitrite as evaluated by dihydrorhodamine oxidation and protein tyrosine nitration on cells. O2·−and peroxynitrite formation were decreased by ascorbate and α-tocopherol. Additionally, CSE led to the oxidation of endothelial nitric oxide synthase increasing the monomeric inactive form of endothelial nitric oxide synthase. Smokers and age-matched healthy volunteers were supplemented orally with 500 mg ascorbate plus 400 IU all-rac-α-tocopherol every 12 h for 165 days. Smokers had endothelial dysfunction compared with control subjects (95% confidence interval: 2.5, 8.3 vs. 10.6, 14.2; P < 0.05) as assessed by flow-mediated dilation of the brachial artery, and plasma levels of protein 3-nitrotyrosine were 1.4-fold higher. The loss of flow-mediated dilation in smokers reverted after a long-term antioxidant supplementation (95% confidence interval: 13.9, 19.9; P < 0.05), reaching values comparable with the control population. Our data indicate that elements on tobacco smoke, most likely through redox cycling, divert·NO toward peroxynitrite by inducing O2·−production in vascular endothelial cells both in vitro and in vivo.

scholarly journals Effect of Gelatin-Based Edible Coatings Incorporated with Aloe vera and Black and Green Tea Extracts on the Shelf Life of Fresh-Cut Oranges

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Mohsen Radi ◽  
Elham Firouzi ◽  
Hamidreza Akhavan ◽  
Sedigheh Amiri
Keyword(s):  
Weight Loss ◽  
Shelf Life ◽  
Green Tea ◽  
Microbial Growth ◽  
Aloe Vera ◽  
Black Tea ◽  
Quality Parameters ◽  
Fresh Cut ◽  
Green And Black Tea ◽  
Tea Extract

The aim of this study was to evaluate the effect of gelatin coating incorporated with Aloe vera gel (50,100%) and green and black tea extracts (5,10%) on physicochemical, microbial, and sensorial properties of fresh-cut oranges at 4°C for 17 days. Significant differences in terms of quality parameters were observed between the control and coated fresh-cut oranges. The highest variation of quality parameters was observed in control, while the least variations were observed in coated slices with 100% Aloe vera and 10% green tea extract. The weight loss was increased with time, but the coating treatment especially with 100% Aloe vera had significant effect on the prevention of weight loss. Also, Aloe vera coated samples obtained the highest score in sensory evaluation. Coating with gelatin incorporated with Aloe vera and green tea extracts successfully retarded the microbial growth and therefore extended the shelf life of fresh-cut oranges during cold storage.

scholarly journals Characteristics of Kombucha Fermentation from Different Substrates and Cytotoxicity of Tea Broth

2018 ◽  
Vol 4 ◽  
pp. 11-19 ◽  
Author(s):  
Maria Elma Quiao-Won ◽  
Franco G. Teves
Keyword(s):  
Green Tea ◽  
Ph Value ◽  
Sugar Content ◽  
Carbon Sources ◽  
Nitrogen Sources ◽  
Black Tea ◽  
Brown Sugar ◽  
Beneficial Effects ◽  
Brine Shrimp Lethality Assay ◽  
Acute And Chronic Effects

Kombucha is made from sweetened tea fermented by a symbiotic culture of bacteria and yeast consumed worldwide because of its potentially beneficial effects on health. However, there are only few studies on the safety of kombucha consumption that will establish it as a functional beverage. The present study compared, pH, temperature and sugar content of different tea mixtures of black or green tea as nitrogen sources and white and brown sugar as carbon sources in a 30-day fermentation period. A marked decrease in pH was observed throughout fermentation with Green tea-White (GW) sugar mixture showing the lowest recorded pH value of 2.37 on the 14th day of fermentation. Temperature is essential in the fermentation process and thus maintained at ambient 29±1°C. Black and green teas with white sugar (7°Brix) showed to have higher sugar level compared to tea mixtures with brown sugar (5°Brix). Brine Shrimp Lethality Assay was carried out to determine cytotoxicity of kombucha. The four substrate combinations have very low LC50 values with Black tea-Brown sugar (BB) mixture showing to have the lowest in both acute and chronic effects (0.073 ppm and 0.101 ppm, respectively). This indicates safety of kombucha for consumption.

scholarly journals Health Benefits of Aqueous Extract of Black and Green Tea Leaves

2020 ◽  
Author(s):  
Zainab Khudhur Ahmad Al-Mahdi ◽  
Ruqaya M.J. Ewadh ◽  
Nada Khazal Kadhim Hindi
Keyword(s):  
Cardiovascular Diseases ◽  
Pathogenic Bacteria ◽  
Black Tea ◽  
Epidemiological Studies ◽  
Tea Plant ◽  
Polyphenolic Compounds ◽  
Tea Consumption ◽  
Beneficial Effects ◽  
Green Tea Leaves ◽  
Green And Black Tea

Tea, next to water, is the beverage humans consume. Drinking the beverage tea is great for joining and collecting family members and public communities since ancient times. Tea plant Camellia sinensis has been cultivated for thousands of years, and its leaves have been used for medicinal purposes. Various studies suggest that polyphenolic compounds present in green and black tea are associated with beneficial effects in prevention of cardiovascular diseases, particularly of atherosclerosis and coronary heart disease. Anti-ageing, antidiabetic and many other health beneficial effects associated with tea consumption are described. Evidence is accumulating that catechins and theaflavins, which are the main polyphenolic compounds of green and black tea, respectively, are responsible for most of the physiological effects of tea. This review describes the evidence from clinical and epidemiological studies in the prevention of chronic diseases like cancer and cardiovascular diseases and inhibits pathogenic bacteria and general health promotion associated with tea consumption.

scholarly journals Acute cognitive, mood and cardiovascular effects of green and black tea

2020 ◽  
Vol 79 (OCE2) ◽  
Author(s):  
Andrew Scholey ◽  
Alicia Burns ◽  
Matt Pase ◽  
Andrew Pipingas
Keyword(s):  
Green Tea ◽  
Diastolic Pressure ◽  
Systolic Pressure ◽  
Cardiovascular Function ◽  
Cardiovascular Effects ◽  
Black Tea ◽  
Assessment System ◽  
Taste Masking ◽  
Double Blind ◽  
Green And Black Tea

AbstractTea is often described as having “refreshing” properties. Indeed, components of both green and black tea have been shown to acutely improve aspects of cognition and mood and to affect cardiovascular function. There is, however, surprising little research directly comparing these effects between different types of tea. This study therefore examined acute cognitive, mood, and cardiovascular effects of green tea and black tea.A double blind, randomised, placebo-controlled,balanced, three-way cross-over study was conducted. Fourteen healthy young adults (M = 23.8, SD = 3 years) consumed placebo (water), green tea and black tea in balanced order at least 24 h apart.The drinks were prepared according to standardised procedures and consumed under double-blind conditions (in opaque containers with lemon cordial added for taste-masking). Mood and cognition were measured at baseline then 90 min post-treatment, cardiovascular function was assessed post-dose only. Mood was evaluated using a series of visual analogue scales, cognitive performance was assessed using a suite of standardised tests from the Computerised Mental Performance Assessment System (COMPASS), gauging performance on aspects of attention, memory and executive function.Peripheral and central systolic and diastolic pressure,augmentation pressure, augmentation index,and blood flow velocity were measured via Sphygmocor pulse wave analysis and Doppler ultrasound, respectively. There were a number of significant effects associated with the active treatments. Compared with placebo, black tea and green tea was associated with significantly improved digit vigilance accuracy (p < .01), while green tea was associated with higher alertness (p < .05).Regarding cardiovascular outcomes, black tea and green tea significantly increased central diastolic pressure, and peripheral diastolic pressure in comparison to placebo (P < .01). Black tea also significantly increased central systolic pressure compared to green tea and placebo (p < .05). Analysis of treatment guessing suggested that the masking procedure was highly effective. In conclusion, the present study shows that green tea improves alertness. Since black tea contains higher levels of caffeine, this effect is likely underpinned by non-caffeine mechanisms or caffeine/non-caffeine compound interactions.Improved vigilance is consistent with caffeine effects which may be modulated by cardiovascular effects. Interestingly the cardiovascular effects are opposite to those reported for chronic tea interventions. These results suggest that acute cognitive and cardiovascular components of tea merit further investigation both in the presence and absence of caffeine.

scholarly journals The Influence of Water Composition on Flavor and Nutrient Extraction in Green and Black Tea

Nutrients ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 80 ◽  
Author(s):  
Melanie Franks ◽  
Peter Lawrence ◽  
Alireza Abbaspourrad ◽  
Robin Dando
Keyword(s):  
Green Tea ◽  
Tap Water ◽  
Epigallocatechin Gallate ◽  
Black Tea ◽  
Deionized Water ◽  
Water Composition ◽  
The Everyday ◽  
Influence Of Water ◽  
Green And Black Tea ◽  
Degree Of Extraction

Tea is made from the processed leaves of the Camellia sinensis plant, which is a tropical and subtropical evergreen plant native to Asia. Behind water, tea is the most consumed beverage in the world. Factors that affect tea brewing include brewing temperature, vessel, and time, water-to-leaf ratio, and, in some reports, the composition of the water used. In this project, we tested if the water used to brew tea was sufficient to influence perceived flavor to the everyday tea drinker. Black and green tea were brewed with bottled, tap, and deionized water, with brewing temperature, vessel, time, and the water-to-leaf ratio matched. The samples were analyzed with a human consumer sensory panel, as well as instrumentally for color, turbidity, and Epigallocatechin Gallate (EGCG) content. Results showed that the type of water used to brew tea drastically affected sensory properties of green tea (and mildly also for black tea), which was likely driven by a much greater degree of extraction of bitter catechins in teas brewed with more purified bottled or deionized water. For the everyday tea drinker who drinks green tea for health, the capability to double the EGCG content in tea by simply brewing with bottled or deionized water represents a clear advantage. Conversely, those drinking tea for flavor may benefit from instead brewing tea with tap water.

Effect of black tea consumption on brachial artery flow-mediated dilation and ischaemia–reperfusion in humans

2014 ◽  
Vol 39 (2) ◽  
pp. 145-151 ◽  
Author(s):  
Tim H.A. Schreuder ◽  
Thijs M.H. Eijsvogels ◽  
Arno Greyling ◽  
Richard Draijer ◽  
Maria T.E. Hopman ◽  
...  
Keyword(s):  
Endothelial Function ◽  
Brachial Artery ◽  
Black Tea ◽  
Hot Water ◽  
Flow Mediated Dilation ◽  
Tea Consumption ◽  
Ischaemia Reperfusion ◽  
Artery Flow ◽  
The Impact

Tea consumption is associated with reduced cardiovascular risk. Previous studies found that tea flavonoids work through direct effects on the vasculature, leading to dose-dependent improvements in endothelial function. Cardioprotective effects of regular tea consumption may relate to the prevention of endothelial ischaemia–reperfusion (IR) injury. Therefore, we examined the effect of black tea consumption on endothelial function and the ability of tea to prevent IR injury. In a randomized, crossover study, 20 healthy subjects underwent 7 days of tea consumption (3 cups per day) or abstinence from tea. We examined brachial artery (BA) endothelial function via flow-mediated dilation (FMD), using high resolution echo-Doppler, before and 90 min after tea or hot water consumption. Subsequently, we followed a 20-min ischaemia and 20-min reperfusion protocol of the BA after which we measured FMD to examine the potential of tea consumption to protect against IR injury. Tea consumption resulted in an immediate increase in FMD% (pre-consumption: 5.8 ± 2.5; post-consumption: 7.2 ± 3.2; p < 0.01), whilst no such change occurred after ingestion of hot water. The IR protocol resulted in a significant decrease in FMD (p < 0.005), which was also present after tea consumption (p < 0.001). This decline was accompanied by an increase in the post-IR baseline diameter. In conclusion, these data indicate that tea ingestion improves BA FMD. However, the impact of the IR protocol on FMD was not influenced by tea consumption. Therefore, the cardioprotective association of tea ingestion relates to a direct effect of tea on the endothelium in humans in vivo.

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